JP2000086748A - New polyester pellet and production of polyester pellet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyester pellet excellent in gas barrier properties, transparency and heat resistance and scarcely generating acetaldehyde. SOLUTION: This polyester pellet comprises a polyester composed of dicarboxylic acid constituent units derived from dicarboxylic acids containing terephthalic acid and isophthalic acid and diol constituent units derived from diols containing ethylene glycol and 1,3-bis(2- hydroxyethoxy)benzene, containing (1) 15-99.5 mol% of the constituent unit derived from the terephthalic acid based on the total dicarboxylic acid constituent units and 0.5-85 mol% of the constituent unit derived from the isophthalic acid based on the total dicarboxylic acid constituent units and (2) 25-99.5 mol% of the constituent unit derived from the ethylene glycol based on the total diol constituent units and 0.5-75 mol% of the constituent unit derived from the 1,3-bis(2-hydroxyethoxy) benzene based on the total diol constituent units and having an intrinsic viscocity within the range of 0.5-1.5 dL/g and the melting point [Tm ( deg.C)] measured by a scanning differential calorimeter satisfying the formula, [1/527-0.0017.ln(1-(mI+ mB)/200)]-1-273<Tm<265 [mI denotes the ratio (mold) of the constituent unit derived from the isophthalic acid in the total dicarboxylic acid constituent units; mB denotes the ratio (mol%) of the constituent unit derived from the 1,3-bis(2-hydroxyethoxy)benzene in the total diol constituent units]. Furthermore, the polyester pellet has >=1,350 kg/m3 density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel polyester pellet and a method for producing the polyester pellet, and more particularly to a polyester pellet excellent in gas barrier properties, transparency and heat resistance of a molded article, and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Saturated polyesters such as polyethylene terephthalate are widely used as containers such as bottles because of their excellent gas barrier properties, transparency and mechanical strength.

[0003] In particular, bottles obtained by biaxially stretch blow molding polyethylene terephthalate have excellent transparency, mechanical strength, heat resistance, and gas barrier properties, and are used for filling beverages such as juices, soft drinks, and carbonated drinks. Container (PET
Widely used as bottles).

[0004] Such a bottle is generally formed by injection molding a saturated polyester to form a preform having a plug portion and a body portion, and then inserting the preform into a mold having a predetermined shape and stretching the preform. It has been manufactured as a bottle having a mouthpiece and an elongated body by blow molding and stretching the body.

[0005] Among such polyester bottles,
In particular, polyester bottles used for beverages such as juices are required to have heat resistance that can cope with heat sterilization of the contents, so the bottles are usually further heat-treated (heat-set) after blow molding to improve heat resistance. Let me.

In addition, the polyester bottle manufactured as described above has a non-stretched plug portion and is inferior in mechanical strength and heat resistance as compared with a stretched trunk portion.
For this reason, usually, the plug portion of the preform is heated and crystallized before blow molding, or the plug portion of the bottle obtained by blow molding is heated and crystallized, and the mechanical strength of the plug portion, Heat resistance etc. are improved.

In recent years, bottles produced from polyester resins (particularly, polyethylene terephthalate) have tended to be miniaturized.
Since the area in contact with the bottle body per unit volume is increased, the effect on the contents due to gas loss or permeation of oxygen from the outside becomes remarkable, and the storage period of the contents is reduced. For this reason, polyester resins are required to have better gas barrier properties than before.

[0008] As an attempt to improve the heat resistance and gas barrier properties of such a polyester resin, it has been proposed to blend polyethylene terephthalate with polyethylene isophthalate or the like (for example, Japanese Patent Publication No. HEI 10-202).
1-22302 gazette). However, in such a blend of polyethylene terephthalate and polyethylene isophthalate, acetaldehyde is generated at the time of melt-kneading at a high temperature performed to increase compatibility, or the taste of the content filled in the container is reduced, In addition, there are problems such as a decrease in transparency, and furthermore, polyethylene isophthalate adheres to the screw and burns due to long-term retention. In addition, when polyethylene isophthalate is amorphous, it is necessary to dry polyethylene terephthalate in a usual dryer, then cool, blend polyethylene terephthalate and polyethylene isophthalate in a dry state, and mold. There were problems such as the cost of equipment required until the machine was put into operation, and the necessity of a larger space for installing the equipment.

For this reason, polyesters comprising a dicarboxylic acid component containing terephthalic acid as a main component, isophthalic acid and ethylene glycol have been proposed. However, heat resistance and gas barrier properties are not always sufficient, and acetaldehyde is not sufficient. May occur, more heat resistance,
There is a demand for a polyester which has excellent gas barrier properties and generates little acetaldehyde.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and is a polyester which is excellent in gas barrier properties, transparency and heat resistance, generates little acetaldehyde, and is crystallized. It is an object to provide a pellet and a method for producing the polyester pellet.

[0011]

SUMMARY OF THE INVENTION A novel polyester pellet according to the present invention comprises a dicarboxylic acid structural unit derived from a dicarboxylic acid containing terephthalic acid and isophthalic acid, ethylene glycol and 1,3-bis (2-hydroxyethoxy) benzene. And (i) 15 to 99.5 mol% of a structural unit derived from terephthalic acid, based on all dicarboxylic acid structural units, and a diol structural unit derived from isophthalic acid. 0.5 to 8 structural units
(Ii) 25 to 9 structural units derived from ethylene glycol, based on all diol structural units.
9.5 mol%, 1,3-bis (2-hydroxyethoxy)
Structural unit derived from benzene is 0.5 to 75 mol%
Having an intrinsic viscosity in the range of 0.5 to 1.5 dl / g and a melting point (Tm (° C.)) measured by a differential scanning calorimeter,
[1 / 527-0.0017 · ln (1- (m _I + m _B ) / 200)] ⁻¹ -273 <Tm ≦ 265… [I] In the formula, m _I is the ratio (mol%) of the constituent units derived from isophthalic acid in all the dicarboxylic acid constituent units, and m _B is derived from 1,3-bis (2-hydroxyethoxy) benzene in the whole diol constituent units. (Indicates the ratio (mol%) of the constituent units used)
It is characterized by having a density of 1350 kg / m ³ or more.

The melting point (Tm (° C.)) of the polyester is
It is desirable that the following general formula [I '] be satisfied. [1 / 527-0.0017 · ln (1- (m _I + m _B ) / 200)] ⁻¹ -270 <Tm ≦ 265 ... [I ′] Further, the polyester pellet has an acetaldehyde content of 20 ppm or less. Preferably, especially 1
It is preferably 0 ppm or less.

The method for producing a polyester pellet according to the present invention comprises: [A] polyethylene terephthalate having an intrinsic viscosity of 0.3 to 0.8 dl / g before solid phase polymerization; 99 to 20% by weight;
[B] a dicarboxylic acid structural unit derived from a dicarboxylic acid containing terephthalic acid and isophthalic acid, and a diol structural unit derived from a diol containing ethylene glycol and 1,3-bis (2-hydroxyethoxy) benzene A polyethylene isophthalate copolymer having an intrinsic viscosity of 0.3 to 0.9 dl / g before solid-phase polymerization; 1 to 80% by weight, blending the mixture, pelletizing, and crystallizing. And

It is preferable that the above-mentioned blend is subjected to solid-phase polymerization after pre-crystallization by heating. The temperature-rise crystallization temperature of the blend is preferably 190 ° C. or lower.

The method for producing polyester pellets according to the present invention comprises: [C] polyethylene terephthalate having an intrinsic viscosity of 0.5 to 1.5 dl / g after solid phase polymerization; 99 to 20% by weight; [B] terephthalic acid A dicarboxylic acid structural unit derived from a dicarboxylic acid containing ethylene and isophthalic acid, and a diol structural unit derived from a diol containing ethylene glycol and 1,3-bis (2-hydroxyethoxy) benzene. Is from 0.3 to 0.9 dl / g, a polyethylene isophthalate copolymer before solid phase polymerization; 1 to 80% by weight
After blending and pelletizing the blend,
It is characterized by crystallization. In the present invention, after crystallization, solid-phase polymerization may be performed as necessary.

In the method for producing polyester pellets according to the present invention, the polyethylene isophthalate copolymer [B]
Is (i) 50 to 98 mol% of a structural unit derived from isophthalic acid, based on all dicarboxylic acid structural units,
The structural unit derived from terephthalic acid is 2 to 50 mol%, (ii) the structural unit derived from ethylene glycol is 15 to 99 mol%, based on all diol structural units, and 1,3-bis ( It is preferred that the content of the structural unit derived from 2-hydroxyethoxy) benzene is 1 to 85 mol%.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the polyester pellets according to the present invention and the method for producing the same will be specifically described.

[New Polyester Pellet] The polyester pellet according to the present invention comprises a dicarboxylic acid structural unit derived from a dicarboxylic acid containing terephthalic acid and isophthalic acid, ethylene glycol and 1,3-bis (2-hydroxyethoxy). ) And a diol constituent unit derived from a diol containing benzene.

The dicarboxylic acid structural unit is derived from isophthalic acid in an amount of 15 to 99.5 mol%, preferably 50 to 99 mol%, of the structural unit derived from terephthalic acid, based on all dicarboxylic acid structural units. The constituent unit to be added is 0.
In the range of 5 to 85 mol%, preferably 1 to 50 mol%,
It is preferred to contain.

Such a polyester may contain a dicarboxylic acid structural unit other than isophthalic acid and terephthalic acid in an amount of less than 20 mol% as long as the object of the present invention is not impaired.

Examples of other dicarboxylic acids which may be contained in an amount of less than 20 mol% include phthalic acid (orthophthalic acid), 2,6-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid.
Aromatic dicarboxylic acids such as 7-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, etc. Aliphatic dicarboxylic acids such as aliphatic dicarboxylic acids and cyclohexanedicarboxylic acid are exemplified.

These dicarboxylic acids may be ester derivatives thereof, or may be a combination of two or more. The diol constituent unit is a constituent unit derived from ethylene glycol in an amount of 25 to 99.5 mol%, preferably 35 to 99.5, based on all diol constituent units.
In the range of 0.5 to 75 mol%, more preferably 0.5 to 75 mol%, preferably 0.5 to 75 mol%, of the structural unit derived from 1,3-bis (2-hydroxyethoxy) benzene.
5 to 65 mol%, more preferably 0.5 to 50 mol%
Is preferably included in the range.

Further, the polyester may contain a diol structural unit other than ethylene glycol and 1,3-bis (2-hydroxyethoxy) benzene in an amount of less than 15 mol% as long as the object of the present invention is not impaired. May be contained.

Other diols which may be contained in an amount of less than 15 mol% include diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylene glycol, propylene glycol, butanediol, pentanediol, and the like. Aliphatic glycols such as neopentyl glycol, hexamethylene glycol, dodecamethylene glycol, alicyclic glycols such as cyclohexane dimethanol, 1,2-bis (2
Glycols containing an aromatic group such as -hydroxyethoxy) benzene, 1,4- (2-hydroxyethoxy) benzene,
Examples include aromatic diols such as bisphenols, hydroquinone, and 2,2-bis (4-β-hydroxyethoxyphenyl) propane.

These diols may be an ester derivative thereof or a combination of two or more. As other diols, diethylene glycol is preferable among these.

Further, such a polyester is derived from a polyfunctional carboxylic acid having three or more carboxyl groups or a polyhydric alcohol having three or more hydroxy groups as long as the object of the present invention is not impaired. A unit derived from a polyfunctional carboxylic acid and / or a unit derived from a polyhydric alcohol may be independently added to the dicarboxylic acid unit in an amount of 0.01 to 100 mol%. ~ 5 mol%, preferably 0.05
To 3 mol%, more preferably 0.1 to 1.5 mol%.

The intrinsic viscosity of the polyester constituting the pellet according to the present invention measured in o-chlorophenol at 25 ° C. is 0.50 to 1.5 dl / g, preferably 0.60 to 1.5 dl / g, more preferably 0.7 to 1.5 dl / g. It is desirable to be in the range of 0.9 dl / g.

Further, such a polyester has a melting point (Tm (° C.)) measured by a differential scanning calorimeter which satisfies the following general formula [I]. [1 / 527-0.0017 · ln (1- (m _I + m _B ) / 200)] ⁻¹ -273 <Tm ≦ 265… [I] (where m _I is isophthalic acid in all dicarboxylic acid constituent units) Ratio (mol%) of the structural unit derived from styrene, and m _B indicates the ratio (mol%) of the structural unit derived from 1,3-bis (2-hydroxyethoxy) benzene in all the diol structural units.)
Further, the melting point (Tm (° C.)) is further represented by the following general formula:
It is desirable to satisfy [I '].

[1 / 527-0.0017 · ln (1- (m _I + m _B ) / 200)] ⁻¹ -270 <Tm ≦ 265 ... [I ′] In the above general formulas [I] and [I ′] , Preferably Tm is 257
C. or lower, more preferably 254.degree. C. or lower.

The polyester pellets according to the present invention composed of such a polyester have a density of 1350 kg / m ^3.
Or more, preferably 1355kg / m ³ or more, more preferably 1360k
g / m ³ or more, more preferably 1380 kg / m ³ or more.

Such a polyester has a heat of crystallization at the time of temperature rise of usually 5 J / g or more, preferably 7 to 4 J / g.
It is desirable to be in the range of 0 J / g. The polyester pellets according to the present invention preferably have an acetaldehyde content of 20 ppm or less, particularly preferably 10 ppm or less.

The size and shape of the polyester pellet according to the present invention are not particularly limited, and are appropriately selected according to the use of the pellet to be used. Examples of the shape include a columnar shape, an elliptical columnar shape, a spherical shape, and an elliptical spherical shape. The size of the pellet is not particularly limited, but the average particle size is 2.0 to 5.0 m.
Those having a size of about m are generally used.

Such polyester pellets of the present invention can be produced by the following production methods (1) and (2). Such polyester pellets may, if necessary, contain additives usually added to polyester, for example, a colorant, an antioxidant, an oxygen absorber, an ultraviolet absorber, an antistatic agent, and a flame retardant. . Further, a recycled PET product may be optionally blended as needed. Furthermore, the polyester pellets may contain a resin other than polyester, for example, polyethylene, ionomer, polypropylene, and polyester elastomer, if necessary.

The polyester pellets according to the present invention can be blended with other resins and additives, if necessary, to be used as a material for various molded articles such as preforms, bottles, (stretched) films and sheets. it can. Also,
These molded articles are a laminate in which at least one layer is a layer molded from the polyester pellet of the present invention, or a laminate in which at least one layer is a layer formed from a blend of the polyester pellet of the present invention and another resin. It may be. This layer may be used for any of the inner layer, the outer layer, and the intermediate layer. As a resin constituting another layer,
Examples thereof include polyesters such as polyethylene terephthalate and polyethylene isophthalate, polyamides such as nylon 6, and ethylene / vinyl acetate copolymer. Of these, polyethylene terephthalate is particularly preferred.

The bottle made from such polyester pellets has excellent gas barrier properties, transparency and heat resistance. Further, since the generation of acetaldehyde is small, the taste of contents such as juice does not decrease.

Next, a method for producing a polyester pellet according to the present invention will be described. [Method for Producing Polyester Pellets (1)] The method for producing polyester pellets according to the present invention is as follows.
Polyethylene terephthalate before solid phase polymerization of 0.8 to 0.8 dl / g; 99 to 20% by weight; [B] intrinsic viscosity of 0.3 to 0.9 dl / g
g, a polyethylene isophthalate copolymer before solid phase polymerization; 1 to 80% by weight is blended, and the blend is pelletized, then crystallized, and preferably further solid phase polymerized.

Polyethylene terephthalate [A] Polyethylene terephthalate [A] used in the present invention
Is composed of a dicarboxylic acid unit derived from terephthalic acid or its ester derivative, and a diol unit derived from ethylene glycol or its ester derivative.

When the dicarboxylic acid unit of the polyethylene terephthalate [A] is 100 mol%,
80 mol% or more of terephthalic acid units, preferably 85 to 85 mol%
It is contained in an amount of 100 mol%.

Other dicarboxylic acids which may be contained in an amount of 20 mol% or less include phthalic acid (orthophthalic acid), isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalene. Aromatic dicarboxylic acids such as dicarboxylic acid, 2,5-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid,
Examples include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, sebacic acid, azelaic acid, and decanedicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.

These dicarboxylic acids may be ester derivatives or a combination of two or more. As the other dicarboxylic acid, isophthalic acid is preferable among them.

When the diol unit of polyethylene terephthalate [A] is 100 mol%, the ethylene glycol unit is at least 80 mol%, preferably 85 mol%.
Desirably, it is contained in an amount of about 100 mol%.

Examples of other diols which may be contained in an amount of 20 mol% or less include diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylene glycol, propylene glycol, butanediol, pentanediol, and the like. Aliphatic glycols such as neopentyl glycol, hexamethylene glycol, dodecamethylene glycol, alicyclic glycols such as cyclohexane dimethanol, 1,2-bis (2
Glycols containing aromatic groups such as (-hydroxyethoxy) benzene, 1,3-bis (2-hydroxyethoxy) benzene, 1,4- (2-hydroxyethoxy) benzene, bisphenols, hydroquinone, 2,2-bis And aromatic diols such as (4-β-hydroxyethoxyphenyl) propane.

These diols may be ester derivatives, and these diols may be a combination of two or more. As other diols, diethylene glycol, cyclohexanedimethanol and the like are preferable among these.

The polyethylene terephthalate used in the present invention may be a polyfunctional carboxylic acid having three or more carboxyl groups or a polyhydric alcohol having three or more hydroxy groups as long as the object of the present invention is not impaired. May be contained, for example, trimesic acid, polyfunctional carboxylic acids such as pyromellitic anhydride, glycerin, 1,1,1-trimethylolethane, 1,1,1
It may contain units derived from polyhydric alcohols such as 1-trimethylolpropane, 1,1,1-trimethylolmethane, and pentaerythritol.

The polyethylene terephthalate [A] used in the present invention is substantially linear, which is confirmed by the fact that the polyethylene terephthalate [A] is dissolved in o-chlorophenol.

The polyethylene terephthalate [A] used in the present invention has an intrinsic viscosity [η] measured in o-chlorophenol at 25 ° C. of 0.3 to 0.8 dl / g, preferably 0.35 to 0.8 dl / g.
It is desirably 0.75 dl / g, which is after the completion of liquid phase polymerization and before solid phase polymerization.

The melting point of polyethylene terephthalate [A] measured by a differential scanning calorimeter (DSC, heating rate: 10 ° C./min) is usually from 210 to 265 ° C., preferably from 220 to 260 ° C. The transition temperature is usually 50 to 120 ° C., preferably 6
Desirably, the temperature is 0 to 100 ° C.

[0048] Such polyethylene terephthalate
[A] may be pre-crystallized if necessary. The pre-crystallization is usually carried out at 100 to 220 ° C, preferably at 130 to 200 ° C,
It can be performed by heating for about 360 minutes.

Such polyethylene terephthalate
[A] can be produced by a conventionally known method. For example, after the dicarboxylic acid and diol are directly esterified, a germanium compound such as germanium dioxide, an antimony compound such as antimony trioxide and antimony acetate are used. Melt polycondensation in the presence of a polycondensation catalyst such as a titanium compound such as titanium tetraalkoxide, or a dicarboxylic acid ester and a diol, titanium tetrabutoxide, titanium alkoxide such as titanium isopropoxide or cobalt acetate, The transesterification reaction is performed in the presence of a transesterification catalyst such as a metal acetate such as zinc acetate, manganese acetate and calcium acetate. As the transesterification catalyst, titanium tetrabutoxide and zinc acetate are desirable. Thereafter, it can be produced by melt polycondensation in the presence of a polycondensation catalyst such as a germanium compound such as germanium dioxide, antimony trioxide, an antimony compound such as antimony acetate, and a titanium compound such as titanium tetraalkoxide. it can. Such a polycondensation catalyst is 0.000 parts by weight based on a total of 100 parts by weight of a dicarboxylic acid or a dicarboxylic acid ester and a diol.
It is desirably contained in an amount of 5 to 0.1 part by weight, preferably 0.001 to 0.05 part by weight.

Polyethylene isophthalate copolymer [B] The polyethylene isophthalate copolymer [B] used in the present invention comprises a dicarboxylic acid structural unit derived from a dicarboxylic acid containing terephthalic acid and isophthalic acid, and ethylene glycol. And diol constituent units derived from diols containing 1,3-bis (2-hydroxyethoxy) benzene.

The dicarboxylic acid structural unit is such that the structural unit derived from isophthalic acid is 50 to 98 mol%, preferably 60 to 95 mol%, based on all dicarboxylic acid structural units.
In the range, the structural unit derived from terephthalic acid is represented by 2
The content is preferably in the range of ５０50 mol%, preferably in the range of ５〜40 mol%.

Further, such a polyethylene isophthalate copolymer [B] may contain a dicarboxylic acid structural unit other than isophthalic acid and terephthalic acid in an amount of less than 15 mol% as long as the object of the present invention is not impaired. It may be contained.

Examples of other dicarboxylic acids which may be contained in an amount of less than 15 mol% include phthalic acid (orthophthalic acid), 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid,
Aromatic rings such as aromatic dicarboxylic acids such as diphenyldicarboxylic acid and diphenoxyethanedicarboxylic acid, aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, sebacic acid, azelaic acid and decanedicarboxylic acid, and cyclohexanedicarboxylic acid. Group dicarboxylic acids and the like.

These dicarboxylic acids may be ester derivatives thereof, or may be a combination of two or more. The diol constituent unit is a constituent unit derived from ethylene glycol in a range of 15 to 99 mol%, preferably 15 to 90 mol%, more preferably 20 to 88 mol%, based on all diol constituent units. , 1,3-
It is preferable to contain a structural unit derived from bis (2-hydroxyethoxy) benzene in the range of 1 to 85 mol%, preferably 10 to 85 mol%, more preferably 12 to 80 mol%.

Further, the polyethylene isophthalate copolymer [B] used in the present invention may contain ethylene glycol and 1,1, as long as the object of the present invention is not impaired.
Diol structural units other than 3-bis (2-hydroxyethoxy) benzene may be contained in an amount of less than 15 mol%.

Examples of other diols which may be contained in an amount of less than 15 mol% include diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylene glycol, propylene glycol, butanediol, pentanediol, and the like. Aliphatic glycols such as neopentyl glycol, hexamethylene glycol, dodecamethylene glycol, alicyclic glycols such as cyclohexane dimethanol, 1,2-bis (2
Glycols containing an aromatic group such as -hydroxyethoxy) benzene, 1,4- (2-hydroxyethoxy) benzene,
Examples include aromatic diols such as bisphenols, hydroquinone, and 2,2-bis (4-β-hydroxyethoxyphenyl) propane.

These diols may be an ester derivative thereof or a combination of two or more. As other diols, diethylene glycol is preferable among these.

Further, the polyethylene isophthalate copolymer [B] used in the present invention may be the above-mentioned polyethylene terephthalate [A] as long as the object of the present invention is not impaired.
May contain a unit derived from a polyfunctional carboxylic acid having three or more carboxyl groups or a polyhydric alcohol having three or more hydroxy groups, specifically, a polyfunctional carboxylic acid. A unit derived from an acid and / or a unit derived from a polyhydric alcohol,
Independently 0.05 to 100 mol% of dicarboxylic acid units
It may be contained in an amount of 0.4 mol%, preferably 0.1 to 0.35 mol%, more preferably 0.2 to 0.35 mol%.

The intrinsic viscosity [η] of the polyethylene isophthalate copolymer [B] used in the present invention measured in o-chlorophenol at 25 ° C. is 0.3 to 0.9 dl / g, preferably
It is desirably 0.35 to 0.85 dl / g, which is after the completion of liquid phase polymerization and before solid phase polymerization.

The glass transition temperature of the polyethylene isophthalate copolymer measured with a differential scanning calorimeter (DSC, heating rate 10 ° C./min) is usually 40 to 120 ° C., preferably 5 to 120 ° C.
Desirably, the temperature is 0 to 100 ° C.

The polyethylene isophthalate copolymer [B] used in the present invention may be pre-crystallized, if necessary, as in the case of the polyethylene terephthalate [A]. Such a polyethylene isophthalate copolymer can be produced by a conventionally known method.For example, after directly diesterifying the dicarboxylic acid and the diol, a germanium compound such as germanium dioxide, antimony trioxide, Melt polycondensation in the presence of a polycondensation catalyst such as an antimony compound such as antimony acetate or a titanium compound such as titanium tetraalkoxide,
Alternatively, a transesterification reaction between a dicarboxylic acid ester and a diol in the presence of a transesterification catalyst such as titanium alkoxides such as titanium isopropoxide and titanium tetrabutoxide and metal acetates such as cobalt acetate, zinc acetate, manganese acetate and manganese acetate. I do. As the transesterification catalyst, titanium tetrabutoxide and zinc acetate are desirable. Thereafter, it can be produced by melt polycondensation in the presence of a polycondensation catalyst such as a germanium compound such as germanium dioxide, antimony trioxide, an antimony compound such as antimony acetate, and a titanium compound such as titanium tetraalkoxide. it can.

Polyester Blend In the production method according to the present invention, the polyethylene terephthalate [A] is 99 to 20% by weight, preferably 99 to 40% by weight.
% By weight, more preferably 98 to 50% by weight, and the above-mentioned polyethylene isophthalate copolymer [B]; 1 to 80% by weight, preferably 1 to 60% by weight, more preferably 2 to 2% by weight.
50% by weight.

After blending the polyethylene terephthalate [A] and the polyethylene isophthalate copolymer [B] so as to have the above-mentioned composition, the blend is prepared at 260 to 310 ° C. and 2 to 300.
This is performed by melt-kneading for seconds. The kneaded blend is formed into chips (pelletized) by an extruder or the like. The average particle size of the pellets is preferably 2.0 to 5.0 mm.

As described above, polyethylene terephthalate
When blending [A] and the polyethylene isophthalate copolymer [B], a transesterification catalyst, a lubricant and the like may be added as necessary.

Examples of the transesterification catalyst include germanium dioxide, antimony trioxide, antimony acetate, manganese acetate, magnesium acetate, cobalt acetate, calcium acetate, zinc acetate, titanium tetrabutoxide and the like. Such a transesterification catalyst is used in an amount of 0.0005 to 0.1 part by weight, preferably 0.001 to 0.1 part by weight, based on 100 parts by weight of the blend.
Desirably, it is contained in an amount of 05 parts by weight.

Specific examples of the (external) lubricant include magnesium stearate and calcium stearate. Such a lubricant may be externally added in an amount of 0.0005 to 0.1 part by weight, preferably 0.001 to 0.05 part by weight, based on 100 parts by weight of the blend.

The resulting crystallization temperature (Tc
c) is preferably 190 ° C or lower, preferably 180 ° C or lower, more preferably 120 to 170 ° C. In addition, the temperature rise crystallization temperature (Tcc) is measured as follows.

Using a DSC-7 type differential scanning calorimeter manufactured by Perkin Elmer, about 10 mg of a slice from the center of a polyester blend pellet dried at about 140 ° C. under a pressure of about 5 mmHg for about 5 hours or more. It is sealed in a liquid aluminum pan under a nitrogen atmosphere and measured. The measurement conditions were as follows: first, the temperature was raised rapidly from room temperature at a rate of 320 ° C./min, and the mixture was melted and held at 290 ° C. for 10 minutes. Thereafter, the peak temperature of the exothermic peak detected when the temperature is raised at a rate of 10 ° C./min is determined.

The intrinsic viscosity of the obtained blend measured in o-chlorophenol at 25 ° C. is 0.3 to 0.9 dl /
g, preferably 0.35 to 0.85 dl / g. Crystallization of the blend The pellets of the blend thus obtained are then crystallized.

The crystallization is performed by drying the blend in a dry state at a temperature from the glass transition temperature (Tg) to a temperature lower than the melting point,
At a temperature 20 ° C. higher and 40 ° C. or lower than the melting point,
It is performed by holding for 1 to 300 minutes, preferably for 5 to 200 minutes. Specifically, it is carried out by heating to 80 to 210 ° C, preferably 100 to 180 ° C.

The crystallization can be performed in air or in an inert atmosphere. The crystallized polyester blend preferably has a crystallinity of 20 to 50%.

In this crystallization, the so-called solid state polymerization reaction of the polyester does not proceed, and the intrinsic viscosity of the polyester blend after crystallization is almost the same as the intrinsic viscosity of the polyester blend before crystallization. Yes, the difference between the intrinsic viscosity of the polyester blend after crystallization and the intrinsic viscosity of the polyester blend before crystallization is usually 0.0
It is 6 dl / g or less.

By crystallizing the polyester blend in this manner, the content of acetaldehyde contained in the polyester can be reduced. In the present invention, the crystallized blend may be subjected to solid-phase polymerization as needed. (Note that crystallization before solid phase polymerization is sometimes referred to as precrystallization.) Solid phase polymerization is usually performed at 180 to 230 ° C, preferably 190 to 220 ° C.
Done in At the time of solid phase polymerization, it is desirable that the pellets of the blend are dried, and therefore, the pellets of the blend may be dried at 80 to 180 ° C. in advance.

The thus obtained polyester pellet has an intrinsic viscosity of 0.5 to 1.5 dl / g, preferably 0.6 to 1.5 dl / g, more preferably 0.6 to 1.5 dl / g measured in o-chlorophenol at 25 ° C. ~ 1.2 dl / g, 1.1 to 2.5 times, preferably 1.2 times, the intrinsic viscosity of the blend before solid phase polymerization.
Desirably, it is up to 2.0 times.

[0075] The polyester pellets thus obtained may be subjected to a hot water treatment. Hot water treatment
This is performed by immersing the obtained polyester pellets in hot water at 70 to 120 ° C. for 1 to 360 minutes. The catalyst used during the polyester polycondensation reaction can be deactivated by the hot water treatment.

The polyester pellets obtained by the production method according to the present invention may contain, if necessary, additives usually added to polyester, such as coloring agents, antioxidants, oxygen absorbers, ultraviolet absorbers, antistatic agents. And a flame retardant.

The polyester pellets obtained by the production method according to the present invention can be used for preforms, bottles, (stretched)
It can be used as a material for various molded articles such as films and sheets.

The bottle made from such polyester pellets has excellent gas barrier properties, transparency and heat resistance. Further, since the generation of acetaldehyde is small, the taste of contents such as juice does not decrease.

[Production Method of Polyester Pellets (2)]
Another embodiment of the method for producing a polyester pellet according to the present invention is: [C] polyethylene terephthalate having an intrinsic viscosity of 0.5 to 1.5 dl / g after solid-phase polymerization;
[B] a polyethylene isophthalate copolymer having an intrinsic viscosity of 0.3 to 0.9 dl / g before solid phase polymerization;
After blending, after pelletizing the blend,
Crystallization and preferably further solid phase polymerization.

[C] Polyethylene Terephthalate The polyethylene terephthalate [C] used in the present invention.
Is composed of a dicarboxylic acid unit derived from terephthalic acid or its ester derivative, and a diol unit derived from ethylene glycol or its ester derivative.

When the dicarboxylic acid unit of the polyethylene terephthalate [C] is 100 mol%,
80 mol% or more of terephthalic acid units, preferably 85 to 85 mol%
Desirably, it is contained in an amount of 100 mol%.

As other dicarboxylic acids which may be contained in an amount of 20 mol% or less, those specifically exemplified as the above-mentioned polyethylene terephthalate [A] can be mentioned, and isophthalic acid is particularly preferred. .

When the diol unit of polyethylene terephthalate [C] is 100 mol%, the ethylene glycol unit is at least 80 mol%, preferably 85 mol%.
Desirably, it is contained in an amount of about 100 mol%.

Examples of other diols which may be contained in an amount of 20 mol% or less include the same diols as those exemplified for the polyethylene terephthalate [A]. Particularly, diethylene glycol, cyclohexane dimethanol Are preferred.

The polyethylene terephthalate [C] used in the present invention may be a polyfunctional carboxylic acid having three or more carboxyl groups or a polyvalent carboxylic acid having three or more hydroxy groups as long as the object of the present invention is not impaired. It may contain units derived from alcohols, for example, trimesic acid, polyfunctional carboxylic acids such as pyromellitic anhydride, glycerin, 1,1,1-trimethylolethane,
It may contain units derived from polyhydric alcohols such as 1,1,1-trimethylolpropane, 1,1,1-trimethylolmethane, and pentaerythritol.

The polyethylene terephthalate [C] used in the present invention is substantially linear, which is confirmed by the fact that the polyethylene terephthalate [C] is dissolved in o-chlorophenol.

The polyethylene terephthalate [C] used in the present invention has an intrinsic viscosity [η] measured at 25 ° C. in o-chlorophenol of 0.5 to 1.5 dl / g, preferably 0.6 to 1.5 dl / g.
It is desirably 1.1 dl / g, after solid phase polymerization.

The melting point of polyethylene terephthalate [C] measured by a differential scanning calorimeter (DSC, heating rate: 10 ° C./min) is usually from 230 to 270 ° C., preferably from 240 to 270 ° C.
260 ° C., and the glass transition temperature is usually 58-75.
C, preferably 60-70C.

Such polyethylene terephthalate can be produced by a conventionally known method. For example, after directly diesterifying the dicarboxylic acid and diol, a germanium compound such as germanium dioxide, antimony trioxide, Antimony compounds such as antimony acetate, melt polycondensation in the presence of a polycondensation catalyst such as a titanium compound such as titanium tetraalkoxide, or an ester of a dicarboxylic acid and a diol,
The transesterification reaction is performed in the presence of a transesterification catalyst such as titanium alkoxide such as titanium isopropoxide and titanium tetrabutoxide and metal acetate such as cobalt acetate, zinc acetate, manganese acetate, and calcium acetate. As the transesterification catalyst, titanium tetrabutoxide and zinc acetate are desirable. After that, it is melt-polycondensed in the presence of a polycondensation catalyst such as germanium compounds such as germanium dioxide, antimony trioxide, antimony compounds such as antimony acetate, and titanium compounds such as titanium tetraalkoxide, and then solid-phase polymerized. Can be manufactured. The solid state polymerization is carried out by heating the melt polycondensate at a temperature of usually 180 to 230 ° C, preferably 190 to 220 ° C. At the time of solid phase polymerization, the melt polycondensate is desirably dried. Therefore, the melt polycondensate may be dried at 80 to 180 ° C. in advance.

Polyethylene isophthalate copolymer [B] The polyethylene isophthalate copolymer is composed of a dicarboxylic acid structural unit derived from a dicarboxylic acid containing terephthalic acid and isophthalic acid, ethylene glycol and 1,3-bis
(2-hydroxyethoxy) benzene and a diol constituent unit derived from a diol containing benzene, and the same polyethylene isophthalate copolymer [B] exemplified in the production method (1) is used.

Polyester Blend In the production method according to the present invention, the polyethylene terephthalate [C] is 99 to 20% by weight, preferably 99 to 40% by weight.
% By weight, more preferably 98 to 50% by weight, and the above-mentioned polyethylene isophthalate copolymer [B]; 1 to 80% by weight, preferably 1 to 60% by weight, more preferably 2 to 2% by weight.
50% by weight.

After blending the polyethylene terephthalate [C] and the polyethylene isophthalate copolymer [B] so as to have the above composition, the blend is prepared at 260 to 310 ° C. and 30 to 300.
This is performed by melt-kneading for seconds. The blend after kneading is pelletized by an extruder or the like. The average particle size of the pellets is preferably 2.0 to 5.0 mm.

As described above, polyethylene terephthalate
When blending [C] with the polyethylene isophthalate copolymer [B], a transesterification catalyst, a lubricant and the like may be added as necessary in the same manner as in the production method (1).

The intrinsic viscosity of the obtained blend measured in o-chlorophenol at 25 ° C. is 0.3 to 0.9 dl /
g, preferably 0.35 to 0.85 dl / g.
The resulting blend has a heated crystallization temperature (Tcc) of 17
0 ° C or lower, preferably 160 ° C or lower, more preferably 1 ° C or lower.
It is preferably from 00 to 155 ° C.

Crystallization of the blend The pellets of the blend thus obtained are then crystallized. Crystallization is performed by drying the blend at a temperature below the glass transition temperature (Tg) to the melting point, preferably 20 ° C. above the Tg and 40 ° C. or more below the melting point.
It is carried out by holding for 300 minutes, preferably for 5 to 200 minutes. Specifically, it is carried out by heating to 80 to 210 ° C, preferably 100 to 180 ° C. Such crystallization can be performed in air or in an inert atmosphere.

The crystallized polyester blend is
It is desirable that the crystallinity be 20 to 50%. In addition,
In such crystallization, the so-called polyester solid-state polymerization reaction does not proceed, and the intrinsic viscosity of the polyester after crystallization is almost the same as the intrinsic viscosity of the polyester before crystallization, and the intrinsic viscosity of the polyester after crystallization. The difference between the viscosity and the intrinsic viscosity of the polyester before crystallization is usually 0.06 dl / g or less.

In the present invention, after crystallization, the pellets may be subjected to solid phase polymerization. The solid phase polymerization is carried out usually at 180 to 230 ° C, preferably at 190 to 220 ° C, as in the above-mentioned production method (1). At the time of solid phase polymerization, it is desirable that the pellets of the blend are dried, and therefore, the pellets of the blend may be dried at 80 to 180 ° C. in advance.

The polyester pellets thus obtained may be subjected to a hot water treatment in the same manner as in the above-mentioned production method (1). Hydrothermal treatment, the obtained solid-phase polymer, 70 ~
It is performed by immersing in hot water of 120 ° C. for 1 to 360 minutes.

The polyester pellets obtained by the production method according to the present invention may contain, if necessary, additives usually added to polyester, such as coloring agents, antioxidants, oxygen absorbers, ultraviolet absorbers, antistatic agents. And a flame retardant.

The polyester pellets obtained by the production method according to the present invention can be used for preforms, bottles, (stretched)
It can be used as a material for various molded articles such as films and sheets.

The bottle made from such polyester pellets has excellent gas barrier properties, transparency and heat resistance. Further, since the generation of acetaldehyde is small, the taste of contents such as juice does not decrease.

[0102]

The use of the polyester pellets of the present invention greatly simplifies the raw material supply line up to the injection molding machine and the extruder, not only can greatly reduce the equipment cost, but also can be used for a long period of continuous molding. The burning can be greatly reduced in the molded article even if the method is performed. In addition, the obtained molded article is excellent not only in gas barrier properties, transparency and heat resistance, but also in a low amount of acetaldehyde, and also in excellent bottle strength, and is less likely to cause delamination even when a knife is put in the bottle.

[0103]

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

In the examples, each characteristic was measured as follows. Prepare a 1 g / dl sample solution using the intrinsic viscosity o-chlorophenol solvent, measure the solution viscosity using an Ubbelohde capillary viscometer at 25 ° C, and then gradually add o-chlorophenol to reduce the solution viscosity. Measure the solution viscosity on the concentration side, and from those data
Extrapolated to 0% concentration.

Carbon dioxide gas permeability coefficient (gas barrier properties) Gas permeability measurement device GPM- manufactured by GL Sciences Corporation
Using 250, the measurement was performed under the conditions of 23 ° C. and 60% relative humidity.

The film used for the measurement was produced as follows. Stretched film: Using a press molding machine with a mold temperature of 290 ° C
A film having a thickness of 0.3 mm was produced, and this film was rapidly cooled at a cooling mold temperature of 0 ° C. to obtain an amorphous film. The amorphous film is then brought to a temperature above the glass transition temperature (Tg) of 15%.
Simultaneous biaxial stretching was performed 3 × 3 times at a temperature higher by ℃ to obtain a stretched film.

Acetaldehyde content : About 2 g of a test piece is sampled from a molded sample of a sample and freeze-ground by a freeze-mill of SPEX. 1 g of the obtained sample powder is placed in a vial, 2 ml of distilled water is added, and the water and the sample powder are mixed well. After capping, the vial is heated at 120 ° C. for 1 hour. After heating, the mixture was cooled in ice water, and 5 μl of the supernatant was measured with a gas chromatograph (GC-6A, manufactured by Shimadzu Corporation).

Heat of crystallization at elevated temperature Measured using a differential calorimeter (DSC) manufactured by PerkinElmer. 10 mg of the sample was weighed into a sample pan, heated from room temperature to 290 ° C. at a rate of 320 ° C./min under a nitrogen stream, and held for 10 minutes. Thereafter, the temperature was rapidly cooled to 30 ° C., maintained for 10 minutes, and then raised at a rate of 10 ° C./min, and the calorific value was measured from the area of the crystallization temperature peak portion appearing between the glass transition temperature and the melting point.

Melting point The melting point was measured using a differential calorimeter (DSC) manufactured by PerkinElmer. 10 mg of the sample was weighed in a sample pan, kept at 30 ° C. for 10 minutes in a nitrogen stream, and then measured for a peak temperature of a melting point which appeared when the temperature was raised to 290 ° C. at a rate of 10 ° C./min.

An aqueous solution having a predetermined density was prepared by mixing zinc (II) chloride, hydrochloric acid, and water in a thermostat having a density of 23 ° C. After standing for 48 hours or more, the sample was put into an aqueous solution, and the density was determined.

[0111]

Example 1 High-purity polyethylene terephthalate (A-1) 332 g of terephthalic acid and 143 g of ethylene glycol
Was prepared, and 0.042 g of germanium dioxide and 0.080 g of phosphoric acid were added thereto. This slurry was heated to a temperature of 255 ° C. under pressure (absolute pressure: 1.7 kg / cm ² ), and an esterification reaction was carried out until an esterification ratio became 95%, to produce a low polymer. Then, under a reduced pressure of 1 torr, 2
The low polymer is melt polymerized at a temperature of 80 ° C. to produce a prepolymer of polyethylene terephthalate (A-1) having an intrinsic viscosity of 0.615 dl / g, which is extruded from a nozzle into a strand, cut and cut, The pellets were 2.5 mm in diameter and 3.5 mm in height. The elevated crystallization temperature of this prepolymer is 15
8 ° C.

The polyethylene isophthalate copolymer (B-
1) A slurry composed of 299 g of isophthalic acid, 33 g of terephthalic acid, 122 g of ethylene glycol and 21 g of 1,3-bis (2-hydroxyethoxy) benzene was prepared, and 0.042 g of germanium dioxide and 0.080 g of phosphoric acid were added thereto. . This slurry was heated to a temperature of 255 ° C. under pressure (absolute pressure: 1.7 kg / cm ² ), and an esterification reaction was carried out until an esterification ratio became 95%, to produce a low polymer. Subsequently, under a reduced pressure of 1 torr, the above-mentioned low polymer was melt-polymerized at a temperature of 280 ° C. to obtain a prepolymer of polyethylene isophthalate copolymer (B-1) having an intrinsic viscosity of 0.815 dl / g (isophthalic acid: Terephthalic acid (molar ratio) = 90:10, ethylene glycol: 1,3-bis (2
-Hydroxyethoxy) benzene (molar ratio = 85:15), which was extruded from a nozzle into a strand and cut into cylindrical pellets having a diameter of 2.5 mm and a height of 3.5 mm.

[0113] Blends Then, the polyethylene terephthalate (A-1) with respect to 90 parts by weight of polyethylene isophthalate copolymer (B-
What was dry blended so that 1) became 10 parts by weight,
Molding temperature 27 using a 20mmφ single screw extruder manufactured by Thermo
It is melt-kneaded at 5 ° C, extruded from the nozzle into a strand, cut and cut into cylindrical pellets of 2.5 mm in diameter and 3.5 mm in height (C-
1) The pre-heated crystallization temperature of this prepolymer is 146 ° C
Met.

Solid Phase Polymerization Next, the pellet (C-1) obtained above was preliminarily crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then subjected to solid phase polymerization at 210 ° C. for 16 hours under a nitrogen atmosphere. Was.

The intrinsic viscosity of the polyester thus obtained was 0.835 dl / g. The carbon dioxide permeability coefficient of the stretched film obtained from this polyester is 10.5cc
・ Mm / m ²・ day ・ atm, acetaldehyde content is 11pp
m.

[0116]

Example 2 The polyethylene terephthalate (A) prepared in Blend Example 1 was used.
-1) To 60 parts by weight, the polyethylene isophthalate copolymer (B-1) was dry-blended so as to be 40 parts by weight, using a 20 mmφ single screw extrusion molding device manufactured by Thermo Co., Ltd., forming temperature 275. The mixture was melted and kneaded at ℃, extruded into a strand shape from a nozzle and cut to obtain a cylindrical pellet (C-2) having a diameter of 2.5 mm and a height of 3.5 mm. The pre-heating crystallization temperature of this prepolymer was 158 ° C.

Solid Phase Polymerization The obtained pellet (C-2) was preliminarily crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then subjected to solid phase polymerization at 210 ° C. for 16 hours under a nitrogen atmosphere.

The polyester thus obtained is
The limiting viscosity was 0.842 dl / g. Also this polyester
The carbon dioxide permeability coefficient of the stretched film obtained from 6.1 cc
mm / m ^Two・ Day ・ atm, acetaldehyde content is 13ppm
Met.

[0119]

Example 3 Polyethylene terephthalate (A-2) 388 g of dimethyl terephthalate and ethylene glycol 13
A slurry composed of 6 g was prepared, and 0.049 g of manganese acetate tetrahydrate was added thereto, and the mixture was heated to 180 ° C. under normal pressure and reacted until the transesterification rate became 95% to prepare a low polymer. . An additional 0.042 g of germanium dioxide and 0.080 g
After the addition of phosphoric acid, under a reduced pressure of 1 torr, the low polymer was melt polymerized at a temperature of 280 ° C., and the intrinsic viscosity was 0.598 dl / g.
A prepolymer of polyethylene terephthalate (A-2) was extruded from a nozzle into a strand and cut to obtain a cylindrical pellet having a diameter of 2.5 mm and a height of 3.5 mm. The pre-heating crystallization temperature of this prepolymer was 153 ° C.

The polyethylene isophthalate copolymer (B-
2) 350 g of dimethyl isophthalate, 39 dimethyl terephthalate
g, 116 g of ethylene glycol and 21 g of 1,3-bis (2-hydroxyethoxy) benzene were prepared, and 0.049 g of manganese acetate tetrahydrate was added thereto, and the mixture was heated to 180 ° C. under normal pressure to obtain a slurry. The reaction was carried out until the transesterification rate reached 95% to produce a low polymer. After adding an additional 0.042 g of germanium dioxide and 0.080 g of phosphoric acid, 1tor
Under a reduced pressure of r, the above low polymer was melt-polymerized at a temperature of 280 ° C. to obtain a prepolymer of a polyethylene isophthalate copolymer (B-2) having an intrinsic viscosity of 0.826 dl / g (isophthalic acid unit:
Terephthalic acid units (molar ratio) = 90:10, ethylene glycol: 1,3-bis (2-hydroxyethoxy) benzene (molar ratio)
= 85: 15), which was extruded from a nozzle into a strand and cut to obtain a cylindrical pellet having a diameter of 2.5 mm and a height of 3.5 mm.

Blend Then, a dry blend was made so that the polyethylene isophthalate copolymer (B-2) was 10 parts by weight with respect to 90 parts by weight of the above polyethylene terephthalate prepolymer (A-2). The mixture was melt-kneaded at a molding temperature of 275 ° C. using a 20 mmφ single-screw extruder made by the company, extruded into a strand shape from a nozzle and cut to obtain a cylindrical pellet (C-3) having a diameter of 2.5 mm and a height of 3.5 mm. The pre-heating crystallization temperature of this prepolymer was 153 ° C.

Solid Phase Polymerization The pellet (C-3) obtained above was preliminarily crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then heated at 210 ° C. in a nitrogen atmosphere.
For 16 hours.

The intrinsic viscosity of the polyester thus obtained was 0.838 dl / g. The carbon dioxide permeability coefficient of the stretched film obtained from this polyester is 10.2cc
・ Mm / m ²・ day ・ atm with acetaldehyde content of 10pp
m.

[0124]

Example 4 Polyethylene terephthalate (A-3) 332 g of high-purity terephthalic acid and 143 g of ethylene glycol
Was prepared, and 0.042 g of germanium dioxide and 0.080 g of phosphoric acid were added thereto. This slurry was heated to a temperature of 255 ° C. under pressure (absolute pressure: 1.7 kg / cm ² ), and an esterification reaction was carried out until an esterification ratio became 95%, to produce a low polymer. Then, under a reduced pressure of 1 torr, 2
The above-mentioned low polymer is melt-polymerized at a temperature of 80 ° C. to produce a prepolymer of polyethylene terephthalate (A-3) having an intrinsic viscosity of 0.615 dl / g, which is extruded from a nozzle into a strand shape and cut into pieces. The pellets were 2.5 mm in height and 3.5 mm in height. The elevated crystallization temperature of this prepolymer is 158
° C.

The polyethylene isophthalate copolymer (B-
3) A slurry comprising 299 g of isophthalic acid, 33 g of terephthalic acid, 122 g of ethylene glycol and 21 g of 1,3-bis (2-hydroxyethoxy) benzene was prepared, and 0.095 g of antimony acetate and 0.080 g of phosphoric acid were added thereto. . This slurry was heated to a temperature of 255 ° C. under pressure (absolute pressure: 1.7 kg / cm ² ), and an esterification reaction was carried out until an esterification ratio became 95%, to produce a low polymer. Subsequently, under a reduced pressure of 1 torr, the low polymer was melt-polymerized at a temperature of 280 ° C.,
Prepolymer of polyethylene isophthalate copolymer (B-3) with intrinsic viscosity of 0.830 dl / g (isophthalic acid: terephthalic acid
(Molar ratio) = 90:10, ethylene glycol: 1,3-bis (2-hydroxyethoxy) benzene (molar ratio) = 85:15), extruded from the nozzle into a strand and cut, The pellets were 2.5 mm in height and 3.5 mm in height.

Blend Then, a dry blend was made so that the polyethylene isophthalate copolymer (B-3) was 10 parts by weight with respect to 90 parts by weight of the polyethylene terephthalate (A-3) prepolymer. The mixture was melt-kneaded at a molding temperature of 275 ° C. using a 20 mmφ single-screw extrusion molding machine, extruded from a nozzle into a strand, and cut to obtain a cylindrical pellet (C-4) having a diameter of 2.5 mm and a height of 3.5 mm. The pre-heating crystallization temperature of the prepolymer was 146 ° C.

Solid Phase Polymerization The pellet (C-4) obtained above was preliminarily crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then heated at 210 ° C. in a nitrogen atmosphere.
For 16 hours. The intrinsic viscosity of the polyester thus obtained was 0.836 dl / g. The stretched film obtained from this polyester had a carbon dioxide gas transmission coefficient of 10.3 cc · mm / m ² · day · atm and an acetaldehyde content of 11 ppm.

[0128]

Comparative Example 1 The polyethylene terephthalate (A-1) prepolymer obtained in Example 1 was melt-kneaded at a molding temperature of 275 ° C. using a 20 mmφ single screw extruder manufactured by Thermo Co., Ltd., and formed into a strand from a nozzle. Extruded and cut, diameter 2.5m
m, a columnar pellet (C-5) having a height of 3.5 mm. The pre-heating crystallization temperature of this prepolymer was 142 ° C.

The obtained pellet (C-5) was preliminarily crystallized at 170 ° C. for 2 hours under a nitrogen gas stream.
Solid-state polymerization was performed at 210 ° C. for 16 hours. The intrinsic viscosity of the polyester thus obtained was 0.830 dl / g.
The stretched film obtained from this polyester had a carbon dioxide gas permeability coefficient of 16.8 cc · mm / m ² · day · atm and an acetaldehyde content of 14 ppm.

[0130]

Comparative Example 2 A slurry composed of 332 g of polyethylene isophthalate (B-4) isophthalic acid and 142 g of ethylene glycol was prepared, and 0.042 g of germanium dioxide and 0.080 g of phosphoric acid were added thereto. This slurry was heated to a temperature of 255 ° C. under pressure (absolute pressure: 1.7 kg / cm ² ), and an esterification reaction was carried out until an esterification ratio became 95%, to produce a low polymer. Subsequently, under a reduced pressure of 1 torr, the low polymer was melt-polymerized at a temperature of 280 ° C., and the intrinsic viscosity was 0.625 dl /
g of a prepolymer of polyethylene isophthalate (B-4) was produced, extruded from a nozzle into a strand, and cut into cylindrical pellets having a diameter of 2.5 mm and a height of 3.5 mm.

Blend Then, the same polyethylene terephthalate (A) as in Example 1 was used.
-1) 90 parts by weight of the prepolymer, polyethylene isophthalate (B-4) was dry-blended so as to be 10 parts by weight, using a 20 mmφ single screw extrusion molding device manufactured by Thermo Co., Ltd. molding temperature 275. The mixture was melted and kneaded at ℃, extruded into a strand shape from a nozzle and cut to obtain a cylindrical pellet (C-6) having a diameter of 2.5 mm and a height of 3.5 mm. The pre-heating crystallization temperature of this prepolymer was 156 ° C.

Solid Phase Polymerization Next, the pellet (C-6) obtained above was preliminarily crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then subjected to solid phase polymerization at 210 ° C. for 16 hours under a nitrogen atmosphere. Was.

The intrinsic viscosity of the polyester thus obtained was 0.841 dl / g. The stretched film obtained from the polyester pellets had a carbon dioxide gas transmission coefficient of 12.5 cc · mm / m ² · day · atm and an acetaldehyde content of 16 ppm.

[0134]

[Comparative Example 3] Polyethylene terephthalate solid-phase polymer High-purity terephthalic acid 332 g and ethylene glycol 143 g
Was prepared, and 0.042 g of germanium dioxide and 0.080 g of phosphoric acid were added thereto. This slurry was heated to a temperature of 255 ° C. under pressure (absolute pressure: 1.7 kg / cm ² ), and an esterification reaction was carried out until an esterification ratio became 95%, to produce a low polymer. Then, under a reduced pressure of 1 torr, 2
The low polymer is melt polymerized at a temperature of 80 ° C. to produce a prepolymer of polyethylene terephthalate (A-1) having an intrinsic viscosity of 0.615 dl / g, which is extruded from a nozzle into a strand, cut and cut, The pellets were 2.5 mm in diameter and 3.5 mm in height. The elevated crystallization temperature of this prepolymer is 15
8 ° C. Next, the obtained pellets were pre-crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then subjected to solid-state polymerization at 210 ° C. for 16 hours under a nitrogen atmosphere.

Blend Then, the same polyethylene isophthalate copolymer (B-1) as in Example 1 was dried so as to become 10 parts by weight with respect to 90 parts by weight of the polyethylene terephthalate (A-1) solid-phase polymer. The blended material was melt-kneaded at a molding temperature of 275 ° C. using a Thermo Co., Ltd. 20 mmφ single-screw extrusion molding machine, extruded into a strand shape from a nozzle, cut, and was 2.5 mm in diameter and height
A 3.5 mm cylindrical pellet (C-7) was obtained. The heated crystallization temperature of this polyester was 156 ° C.

The columnar pellets (C
-7) to prepare a stretched film. The carbon dioxide gas transmission coefficient of the obtained film was 11.8 cc · mm / m ² · day · atm, and the acetaldehyde content was 22 ppm.

[0137]

Comparative Example 4 Polyethylene Terephthalate Copolymer (A-
4) A slurry comprising 299 g of terephthalic acid, 33 g of isophthalic acid, 122 g of ethylene glycol and 21 g of 1,3-bis (2-hydroxyethoxy) benzene was prepared, and 0.042 g of germanium dioxide and 0.080 g of phosphoric acid were added thereto. . This slurry was heated to a temperature of 255 ° C. under pressure (absolute pressure: 1.7 kg / cm ² ), and an esterification reaction was carried out until an esterification ratio became 95%, to produce a low polymer. Subsequently, the low polymer was melt-polymerized at a temperature of 280 ° C. under a reduced pressure of 1 torr to obtain a polyethylene terephthalate copolymer (A-4) having an intrinsic viscosity of 0.623 dl / g (terephthalic acid: isophthalic acid). Acid (molar ratio) = 90:10, ethylene glycol: 1,3-bis (2
-Hydroxyethoxy) benzene (molar ratio = 85:15), which was extruded from a nozzle into a strand and cut into cylindrical pellets having a diameter of 2.5 mm and a height of 3.5 mm.
The pre-heating crystallization temperature of the prepolymer was 163 ° C.

Next, the pellet obtained above was heated at 170 ° C.
After pre-crystallization for 2 hours in a nitrogen stream, solid-state polymerization was performed at 210 ° C. for 16 hours under a nitrogen atmosphere. The limiting viscosity of the polyester thus obtained is 0.841 dl / g
Met. The carbon dioxide gas permeability constant of the stretched film obtained from the polyester pellets ^{14.2cc · mm / m 2 · day} · a
tm, and the acetaldehyde content was 13 ppm.

[0139]

[Table 1]

[0140]

Embodiment 5 Polyethylene terephthalate (A-5) The first, second, third, fourth and fifth reactors are tank-type, and the sixth reactor is a biaxial rotary horizontal reactor. Was used to carry out continuous polymerization to produce polyethylene terephthalate (A-5).

3750 parts by weight of the reaction solution had been retained in advance, and the high-purity terephthalic acid 143 was added hourly to the first reactor maintained under stirring at 255 ° C. under a nitrogen atmosphere at 1.7 kg / cm ² G.
A slurry prepared by mixing 7 parts by weight and 591 parts by weight of ethylene glycol was continuously supplied to carry out a first-stage esterification reaction. In the first-stage esterification reaction, a mixed solution consisting of 203 parts by weight of water and 3 parts by weight of ethylene glycol was distilled off. The first-stage esterification reaction product was controlled so that the average residence time was 2.0 hours, and 0.8 kg / cm ² G at 260 ° C. with continuous stirring.
Into the second reactor maintained under the following conditions. In this reactor 2, a uniform solution of 0.48 parts by weight of germanium dioxide / hour and 32 parts by weight of ethylene glycol was continuously supplied, and a mixture of 84 parts by weight of water / hour and 5 parts by weight of ethylene glycol was supplied. The liquid was continuously distilled off, and the second-stage esterification reaction product had an average residence time of 2.0.
The time was controlled to a third reactor which was continuously stirred and maintained at 265 ° C. under normal pressure. This third
In the reactor, a uniform solution in which 1.23 parts by weight of trimethyl phosphate / hour and 22 parts by weight of ethylene glycol were mixed was continuously supplied, and 21 parts by weight of water and 27 parts by weight of ethylene glycol were added per hour. The mixture was continuously distilled off, and the third-stage esterification reaction was continued.

The third-stage esterification reaction product was also controlled so that the average residence time was 2.0 hours, and was led to a fourth reactor maintained at 275 ° C. and 60 mmHg with continuous stirring.
In the fourth reactor, a mixture of 45 parts by weight of ethylene glycol and 6 parts by weight of water per hour was continuously distilled off, and the first-stage polycondensation reaction product had an average residence time of 1.0 hour. It was introduced into a fifth reactor which was controlled at 282 ° C. and maintained at 3 mmHg under continuous stirring.

In the fifth reactor, a mixed solution of 20 parts by weight of ethylene glycol / hour and 3 parts by weight of water was continuously distilled off, and the second stage polycondensation reaction was continued. The second-stage polycondensation reaction product had an average residence time of 1.0
Controlled at 282 ° C to 285 ° C continuously for 1.
It was led to a sixth reactor, which was a horizontal twin-screw rotary reaction tank maintained under the conditions of 8 mmHg to 2.5 mmHg.

In the sixth reactor, a mixed solution of 10 parts by weight of ethylene glycol and 1 part by weight of water was continuously distilled off, and the third stage polycondensation reaction was continued.
In addition, the polycondensation reaction product of the third stage is controlled so that the average residence time is 2.5 hours, and is continuously drawn out of the reactor in a strand shape by a polyester extraction device, and immersed in water. After being cooled down, it was cut into pellets by a strand cutter. The polyethylene terephthalate (A-
5) Intrinsic viscosity measured at 25 ° C in o-chlorophenol
[η] was 0.65 dl / g.

The polyethylene isophthalate copolymer (B-
5) A polyethylene isophthalate copolymer (B-5) was produced by using the same apparatus as that for producing the above polyethylene terephthalate (A-5) and operating as follows.

3750 parts by weight of a reaction solution was previously retained, and 1208 parts by weight of isophthalic acid was added to a first reactor kept under stirring at 255 ° C. under a nitrogen atmosphere at 1.7 kg / cm ² G.
A slurry prepared by mixing 135 parts by weight of terephthalic acid, 477 parts by weight of ethylene glycol, 211 parts by weight of 1,3- (bis-2-hydroxyethoxy) benzene and 3.4 parts by weight of 1,1,1-trimethylolpropane was continuously mixed. To perform the first-stage esterification reaction.

The first-stage esterification reaction product was controlled such that the average residence time was 2.0 hours, and was maintained under continuous stirring at 260 ° C. and 0.8 kg / cm ² G. Into the second reactor. In this reactor 2, 1.
A uniform solution of 06 parts by weight of antimony acetate, 0.25 parts by weight of cobalt acetate and 32 parts by weight of ethylene glycol was continuously supplied. The second-stage esterification reaction product was introduced into a third reactor, which was controlled so that the average residence time was 2.0 hours, and was continuously stirred and maintained at 265 ° C. under normal pressure. In the third reactor, a homogeneous solution in which 0.11 part by weight of phosphoric acid and 22 parts by weight of ethylene glycol were mixed per hour was continuously supplied, and the third-stage esterification reaction was continued.

The third-stage esterification reaction product was also controlled so that the average residence time was 2.0 hours, and was led to a fourth reactor maintained at 275 ° C. and 60 mmHg with continuous stirring. No.
The polycondensation reaction product in the four reactors was controlled so that the average residence time was 1.0 hour, and was introduced into the fifth reactor maintained at 282 ° C. and 3 mmHg under continuous stirring.

In the fifth reactor, a mixed solution of 20 parts by weight of ethylene glycol and 3 parts by weight of water was continuously distilled off, and the second stage polycondensation reaction was continued. The second-stage polycondensation reaction product had an average residence time of 1.0
Controlled at 282 ° C to 285 ° C continuously for 1.
It was led to a sixth reactor, which was a horizontal twin-screw rotary reaction tank maintained under the conditions of 8 mmHg to 2.5 mmHg.

In the sixth reactor, a mixture of 10 parts by weight of ethylene glycol and 1 part by weight of water was continuously distilled off per hour, and the third stage polycondensation reaction was continued.
In addition, the polycondensation reaction product in the third stage is controlled so that the average residence time is 2.5 hours, and is continuously withdrawn by a polyester withdrawing device in a strand form outside the reactor, into a pellet form. It was cut. Polyethylene isophthalate copolymer obtained by the above liquid phase polymerization (B-5)
Intrinsic viscosity [η] measured in o-chlorophenol at 25 ℃
Was 0.85 dl / g, isophthalic acid: terephthalic acid (molar ratio) = 90: 10, and ethylene glycol: 1,3-bis (2-hydroxyethoxy) benzene (molar ratio) = 88: 12.

Blend Dry blending was performed so that 10 parts by weight of the polyethylene isophthalate copolymer (B-5) was added to 90 parts by weight of the above polyethylene terephthalate (A-5).
Using a twin screw extruder (TEX-45, manufactured by Japan Steel Works, L / D = 33)
Melt kneading at 280 ° C with screw rotation speed 200rpm, 200kg
/ hr extruded, cut into strands, diameter 2.5mm, height
A 3.5 mm cylindrical pellet was obtained. The residence time in the extruder at this time was 12.2 seconds.

Solid Phase Polymerization Subsequently, the obtained pellets were preliminarily crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then subjected to solid phase polymerization at 210 ° C. for 14 hours under a nitrogen atmosphere.

The polysell thus obtained is
The intrinsic viscosity was 0.848 dl / g. The acetaldehyde content of this polyester pellet was 2 ppm, and the carbon dioxide permeability coefficient of the stretched film formed from this polyester pellet was 10.1 cc · mm / m ² · day · atm.

[0154]

Examples 6 and 7 The same procedures as in Example 5 were carried out except that the mixing ratio of the polyethylene terephthalate (A-5) and the polyethylene isophthalate copolymer (B-5) was as shown in Table 2. Polyester pellets were produced. Table 2 shows the results.

Example 8 The polyethylene terephthalate of Example 5 (A
Instead of -5), polyethylene terephthalate described later
Using (A-7), polyester pellets were prepared in the same manner as in Example 5, except that the mixing ratio of polyethylene terephthalate (A-7) and polyethylene isophthalate copolymer (B-5) was as shown in Table 2. Manufactured. Table 2 shows the results.

Example 9 The blending ratio of (A-5) and (B-5) in Example 5 was as shown in Table 2, and after blending, crystallization was carried out to obtain the same polyester pellets as in Example 5. Manufactured. Table 2 shows the results.

[0155]

[Table 2]

[0156]

Examples 10 to 13 Polyethylene terephthalate (A-
6) Using the same apparatus as that for producing polyethylene terephthalate (A-5) of Example 5, the following operation was carried out to produce polyethylene terephthalate (A-6).

A reaction vessel containing 3750 parts by weight of a reaction solution in advance was stirred at 255 ° C. under a nitrogen atmosphere under a nitrogen atmosphere at 1.7 kg / cm ² G in a first reactor.
A slurry prepared by mixing 8 parts by weight, 29 parts by weight of isophthalic acid and 591 parts by weight of ethylene glycol was continuously supplied, and a first-stage esterification reaction was performed. This first
In the second stage of the esterification reaction, a mixed solution composed of 203 parts by weight of water and 3 parts by weight of ethylene glycol was distilled off. The first-stage esterification reaction product was controlled such that the average residence time was 2.0 hours, and was maintained under continuous stirring at 260 ° C. under a condition of 0.8 kg / cm ² G. It was led to the reactor. In this reactor 2, a uniform solution of 0.94 parts by weight of antimony acetate / hour, 0.10 parts by weight of cobalt acetate and 32 parts by weight of ethylene glycol was continuously supplied, and 84 parts by weight of water / hour and 5 parts by weight of Part of the mixed solution with ethylene glycol was continuously distilled off, and the second-stage esterification reaction product was controlled so that the average residence time was 2.0 hours, and was continuously stirred at 265 ° C. It was led to a third reactor maintained under pressure conditions. In the third reactor, a uniform solution in which 0.10 part by weight of phosphoric acid / hour and 22 parts by weight of ethylene glycol are mixed is continuously supplied, and 21 parts by weight of water and 27 parts by weight of ethylene / hour are continuously supplied. The mixed solution with glycol was continuously distilled off, and the third-stage esterification reaction was continued.

This third-stage esterification reaction product was also controlled so that the average residence time was 2.0 hours, and was led to a fourth reactor maintained at 275 ° C. and 60 mmHg with continuous stirring.
In the fourth reactor, a mixture of 45 parts by weight of ethylene glycol and 6 parts by weight of water per hour was continuously distilled off, and the first-stage polycondensation reaction product had an average residence time of 1.0 hour. The reaction was led to a fifth reactor maintained at 282 ° C. and 3 mmHg under continuous stirring.

In this fifth reactor, a mixed solution of 20 parts by weight of ethylene glycol and 3 parts by weight of water was continuously distilled off, and the second stage polycondensation reaction was continued. The second-stage polycondensation reaction product had an average residence time of 1.0
Controlled at 285 ° C to 287 ° C,
It was led to the sixth reactor, which was a horizontal twin-screw rotary reaction tank maintained under the conditions of 1.8 mmHg to 2.5 mmHg.

In the sixth reactor, a reaction solution of 10 parts by weight of ethylene glycol and 1 part by weight of water was continuously distilled off, and the third stage polycondensation reaction was continued.
In addition, the polycondensation reaction product of the third stage is controlled so that the average residence time is 2.5 hours, and is continuously drawn out of the reactor in a strand shape by a polyester extraction device, and immersed in water. After being cooled down, it was cut into pellets by a strand cutter. The polyethylene terephthalate (A-
6) Intrinsic viscosity measured at 25 ° C in o-chlorophenol
[η] was 0.65 dl / g, and terephthalic acid: isophthalic acid (molar ratio) was 98: 2.

Blend / Polyethylene terephthalate (A-6) was used in place of (A-5), and (A-5) and polyethylene isophthalate copolymer (B-
Blend / solid phase polymerization was carried out in the same manner as in Example 5, except that the weight ratio with respect to 5) was as shown in Table 3. The intrinsic viscosity of the obtained polyester and the acetaldehyde content in the pellet were measured. Further, a stretched film was prepared from the obtained polyester pellets, and the carbon dioxide gas transmission coefficient was measured. Table 3 shows the results.

[0162]

[Table 3]

[0163]

Examples 14 and 15 Polyethylene terephthalate (A-
7) Polyethylene terephthalate (A-6) pellets at 170 ° C
After preliminarily crystallizing under a nitrogen stream for a period of time, solid phase polymerization was performed at 210 ° C. for 8 hours under a nitrogen atmosphere.

The intrinsic viscosity of the polyethylene terephthalate (A-7) thus obtained was 0.850 dl / g. The acetaldehyde content of this polyethylene terephthalate (A-7) was 2 ppm.

The polyethylene terephthalate (A-7) produced above was used in place of the blend / crystallization (A-5), and the copolymer of (A-7) and the polyethylene isophthalate copolymer (B-5) was used. The blending was carried out in the same manner as in Example 5, except that the weight ratio was as shown in Table 4. The obtained pellet was crystallized at 170 ° C. for 2 hours under a nitrogen stream.

The intrinsic viscosity of the obtained polyester and the acetaldehyde content in the pellet were measured. Further, a stretched film was prepared from the obtained polyester pellets, and the carbon dioxide gas transmission coefficient was measured. Table 4 shows the results.

[0167]

[Table 4]

[0168]

Example 16 Polyethylene Terephthalate (A-8) In the above - mentioned method for producing polyethylene terephthalate (A-6), the compound supplied to the first reactor was supplied with 1322 parts by weight of high-purity terephthalic acid and 150 parts by weight of naphthalenedicarboxylic acid per hour. And polyethylene terephthalate (A-8) was obtained in the same manner except that ethylene glycol 591 parts by weight was used. The intrinsic viscosity [η] of the polyethylene terephthalate (A-8) obtained by the above liquid phase polymerization measured at 25 ° C. in o-chlorophenol is 0.64 dl / g, and terephthalic acid: naphthalenedicarboxylic acid (molar ratio) ) = 92: 8.

Blend The blending was carried out in the same manner as in Example 5 except that the polyethylene terephthalate (A-8) produced above was used in place of the solid phase polymerization (A-5). The obtained pellet was crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then subjected to solid-state polymerization at 210 ° C. for 17 hours.

The intrinsic viscosity of the obtained polyester and the acetaldehyde content in the pellet were measured. Further, a stretched film was prepared from the obtained polyester pellets, and the carbon dioxide gas transmission coefficient was measured. Table 5 shows the results.

[0171]

[Table 5]

[0172]

Example 17 90 parts by weight of blended polyethylene terephthalate (A-5)
Using a dry blended polyethylene isophthalate copolymer (B-5) 10 parts by weight, using a vented twin-screw extruder (TEX-45, manufactured by Nippon Steel Works, L / D = 16), Screw rotation speed 400rpm, melt kneading at 280 ℃, 320kg / h
Extrude into a strand with r, cut, diameter 2.5mm, height 3.
A 5 mm cylindrical pellet was obtained. The residence time in the extruder at this time was 4.1 seconds.

Solid Phase Polymerization Next, the obtained pellets were preliminarily crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then subjected to solid phase polymerization at 210 ° C. for 14 hours under a nitrogen atmosphere.

The intrinsic viscosity of the obtained polyester is 0.868 d.
l / g. The acetaldehyde content of this polyester pellet was 2 ppm, and the carbon dioxide permeability coefficient of a stretched film made from this polyester pellet was
It was 9.0 cc · mm / m ² · day · atm. (Table 6)

[0175]

[Table 6]

[0176]

Comparative Example 5 A stretched film was produced using polyethylene terephthalate (A-7) without blending it with another polyester.

The stretched film obtained had a carbon dioxide gas transmission coefficient of 16.2 cc · mm / m ² · day · atm. The acetaldehyde content of the used polyethylene terephthalate (A-7) pellets was 2 ppm.

[0178]

Example 18 A polyester resin composition produced according to Example 5 of carbonated beverage bottle Example 5 and dried at 160 ° C. for 4 hours with air having a dew point of −30 ° C. or less was injected with M-70B manufactured by Meiki Seisakusho Co., Ltd. A bottomed parison (preform) was manufactured using a molding machine.

The injection molding machine used had a screw compression ratio of 1.5, a screw having three ridges with a dalmage type mixing section, and a molding temperature of 28.
Molding was performed at 0 ° C. in a molding cycle of 33 seconds.

Next, the surface temperature of the central part of the body of the preform was adjusted to 100 to 11 by an infrared heater attached to the molding machine.
After heating to 0 ° C., the mixture was biaxially stretched and blown with a LB-01 molding machine manufactured by CORPOPLAST to obtain a bottle for a carbonated beverage having a content of 500 ml. During biaxial stretch blow molding, the temperature of the blow mold was set to normal temperature, and the bottle was brought into contact with the mold for 5 seconds and taken out. The molding cycle at this time was 60 seconds, and the plane stretching ratio was 11 times.

With respect to the thus produced 500 mL bottle, a part of the mouth was cut off, the amount of acetaldehyde was analyzed, and the body of the bottle was cut off to measure the carbon dioxide gas barrier property. Table 7 shows the results.

[0182]

Example 19 A carbonated beverage bottle was prepared in the same manner as in Example 18 except that the polyester produced in Example 10 was used, and a preform was produced, and the bottle was stretch blow-molded. For this bottle, the amount of acetaldehyde at the mouth of the bottle was analyzed in the same manner as in Example 18, and the carbon dioxide barrier property of the body of the bottle was measured. Table 7 shows the results.

[0183]

EXAMPLE 20 except for using a polyester produced by carbonated beverage bottles Example 14, in the same manner as in Example 18, to produce a preform, and stretch blow molding the bottle. For this bottle, the amount of acetaldehyde at the mouth of the bottle was analyzed in the same manner as in Example 18, and the carbon dioxide barrier property of the body of the bottle was measured. Table 7 shows the results.

[0184]

EXAMPLE 21 except for using a polyester produced by heat bottle Example 10, in the same manner as in Example 18, was prepared preform. The mouth of the preform was crystallized by an infrared heater and biaxially stretched and blown by a CORPOPLAST LB-01 molding machine. The mold temperature at this time was 130 ° C. After the bottle was brought into contact with the mold for 5 seconds, room temperature air was blown into the bottle, and the bottle was cooled and taken out of the mold. In the same manner as in Example 18, the amount of acetaldehyde in the mouth of the bottle was analyzed, and the carbon dioxide barrier property of the body of the bottle was measured. Table 7 shows the results.

[0185]

Example 22 Evaluation of Film The polyester produced in Example 10 was heated at 150 ° C.
After drying in vacuum for 16 hours, a 0.3 mm thick film was prepared using a press molding machine at a mold temperature of 290 ° C.
This film was rapidly cooled in a cooling mold at 0 ° C. to obtain an amorphous film.

Next, this amorphous film was heated at 90 ° C. for 3 hours.
It was simultaneously biaxially stretched by a factor of 3 to produce a stretched film.
The amount of acetaldehyde was analyzed using the film before stretching, and the carbon dioxide gas barrier property of the film after stretching was measured. Table 7 shows the results.

[0187]

Example 23 Evaluation of Film Using the polyester produced in Example 12,
A stretched film was prepared in the same manner as in Example 22, and the acetaldehyde content of the film before stretching and the carbon dioxide gas barrier property of the film after stretching were evaluated. Table 7 shows the results.

[0188]

Example 24 Evaluation of Unstretched Sheet The polyester produced in Example 10 and vacuum-dried at 150 ° C. for 16 hours was used, and the cylinder temperature was 275 using an extruder with a cylinder diameter of 50 mmφ manufactured by Hitachi Zosen Corporation. At 0 ° C, a sheet having a thickness of 0.3 mm was formed. The acetaldehyde content and carbon dioxide gas barrier property of the molded article were measured. Table 7 shows the results.

[0189]

[Table 7]

[0190]

Example 25 Carbonated Beverage Bottle Polyester resin composition: 33 parts by weight, prepared according to Example 11 and dried at 160 ° C. for 4 hours with air having a dew point of −30 ° C. or less, and polyethylene terephthalate (A
-7): After dry blending with 67 parts by weight, a bottomed parison (preform) was manufactured using an M-70B injection molding machine manufactured by Meiki Seisakusho Co., Ltd.

The injection molding machine used had a screw compression ratio of 1.5, a screw having three ridges at the tip and having a dalmage type mixing section, and a molding temperature of 28.
Molding was performed at 0 ° C. in a molding cycle of 33 seconds.

Next, the surface temperature of the central part of the body of the preform was adjusted to 100 to 11 by an infrared heater attached to the molding machine.
After heating to 0 ° C., the mixture was biaxially stretched and blown with a LB-01 molding machine manufactured by CORPOPLAST to obtain a bottle for a carbonated beverage having a content of 500 ml. During biaxial stretch blow molding, the temperature of the blow mold was set to normal temperature, and the bottle was brought into contact with the mold for 5 seconds and taken out. The molding cycle at this time was 60 seconds, and the plane stretching ratio was 11 times.

With respect to the thus produced 500 mL bottle, a part of the mouth was cut off, the amount of acetaldehyde was analyzed, and the body of the bottle was cut off to measure the carbon dioxide gas barrier property. Table 8 shows the results.

[0194]

Example 26 Carbonated Drink Bottle Example 25 except that a dry blend of 33 parts by weight of the polyester produced by Example 15 and 67 parts by weight of polyethylene terephthalate (A-7) was used.
In the same manner as in the above, a preform was produced, and the bottle was stretch blow-molded. For this bottle, the amount of acetaldehyde in the mouth of the bottle was analyzed in the same manner as in Example 25, and the carbon dioxide gas barrier properties of the body of the bottle were measured. Table 8 shows the results.

[0195]

Example 27 Carbonated Beverage Bottle Example 25 except that a dry blend of 20 parts by weight of the polyester produced according to Example 12 and 80 parts by weight of polyethylene terephthalate (A-7) was used.
In the same manner as in the above, a preform was produced, and the bottle was stretch blow-molded. For this bottle, the amount of acetaldehyde in the mouth of the bottle was analyzed in the same manner as in Example 25, and the carbon dioxide gas barrier properties of the body of the bottle were measured. Table 8 shows the results.

[0196]

Example 28 A heat-resistant bottle was prepared in the same manner as in Example 25, except that a blend of 33 parts by weight of the polyester produced in Example 11 and 67 parts by weight of polyethylene terephthalate (A-7) was used. A preform was manufactured. The mouth of this preform is crystallized by an infrared heater and manufactured by CORPOPLAST.
It was biaxially stretched and blown with an LB-01 molding machine. The mold temperature at this time was 130 ° C. After the bottle was brought into contact with the mold for 5 seconds, room temperature air was blown into the bottle, and the bottle was cooled and taken out of the mold. Example 2 for this bottle
In the same manner as in 5, the amount of acetaldehyde in the mouth of the bottle was analyzed, and the carbon dioxide barrier property of the body of the bottle was measured. Table 8 shows the results.

[0197]

Example 29 Evaluation of Film The polyester produced in Example 11 was vacuum-dried at 150 ° C. for 16 hours for 16 hours, and 33 parts by weight of polyethylene terephthalate (A-7) were blended with 67 parts by weight of gold. 0.3mm using a press molding machine with a mold temperature of 290 ° C
A film having a thickness is prepared, and the film is cooled at 0 ° C.
Was rapidly cooled under the conditions described above to obtain an amorphous film.

Next, this amorphous film was heated at 90 ° C. for 3 hours.
It was simultaneously biaxially stretched by a factor of 3 to produce a stretched film.
The amount of acetaldehyde was analyzed using the film before stretching, and the carbon dioxide gas barrier property of the film after stretching was measured. Table 8 shows the results.

[0199]

Example 30 Evaluation of Film A stretched film was prepared in the same manner as in Example 29, using a blend of 40 parts by weight of the polyester produced in Example 12 and 60 parts by weight of polyethylene terephthalate (A-7). Was prepared, and the acetaldehyde content of the film before stretching and the carbon dioxide gas barrier property of the film after stretching were evaluated. Table 8 shows the results.

[0200]

Example 31 Evaluation of Unstretched Sheet 33 parts by weight of a polyester produced in Example 11 and vacuum-dried at 150 ° C. for 16 hours, and 67 parts by weight of polyethylene terephthalate (A-7) were blended. A 0.3 mm thick sheet was formed at a cylinder temperature of 275 ° C. by using an extruder having a cylinder diameter of 50 mmφ manufactured by K.K. The acetaldehyde content and carbon dioxide gas barrier property of the molded article were measured. Table 8 shows the results.

[0201]

[Table 8]

[0202]

Example 32 Evaluation of Laminated Bottle The polyester produced in Example 11 was heated at 150 ° C.
The material dried in vacuum for 16 hours was used as a raw material for the intermediate layer (cylinder temperature 210 ° C.), and polyethylene terephthalate (A-
7) as raw material for inner and outer layers (cylinder temperature 270 ° C)
AS manufactured by Nissei ASB Machine Co., Ltd. as an injection blow molding machine
A preform was manufactured using B-50HT so that the thickness of the inner / outer layer / the thickness of the intermediate layer = 67/33, and stretch blow-molded to form a laminated bottle having an inner volume of 500 ml. A part of the mouth of the bottle was cut to analyze the amount of acetaldehyde, and the body of the bottle was cut to evaluate the carbon dioxide gas barrier property. Table 9 shows the results.

[0203]

Example 33 A laminated bottle was molded in the same manner as in Example 32 except that the polyester obtained in Example 15 was used as a raw material for the intermediate layer.
And the product made from carbon dioxide barrier was evaluated. Table 9 shows the results.

[0204]

Example 34 The polyester obtained in Example 12 was used as a raw material for the intermediate layer, and the thickness ratio between the polyester intermediate layer and the inner / outer layers of polyethylene terephthalate (A-7) was as shown in Table 9. A laminated bottle was molded in the same manner as in Example 32 except that the amount of acetaldehyde and the carbon dioxide gas barrier were evaluated. Table 9 shows the results.

[0205]

Example 35 A preform was produced in the same manner as in Example 32. The mouth of the prepared preform was crystallized in the same manner as in Example 21 and then blow-molded. Table 9 shows the results.
Shown in

[0206]

Example 36 The polyester produced in Example 11 was vacuum-dried at 150 ° C. for 16 hours, and used as a raw material for an intermediate layer of a co-extruder manufactured by Hitachi Zosen. A layered sheet having a thickness of 0.3 mm was formed using the material dried in vacuum for 16 hours as a raw material for an inner layer and an outer layer. Next, the laminated sheet was biaxially stretched 3 × 3 times at 90 ° C. to prepare a stretched film. The acetaldehyde amount of the laminated film before stretching and the carbon dioxide gas barrier property of the laminated film after stretching were evaluated. Table 9 shows the results.

[0207]

Example 37 The polyester produced in Example 12 was used as a raw material for the intermediate layer, and the ratio of the thickness of the polyester layer to the polyethylene terephthalate (A-7) layer (inner / outer layer) was 40:60. A laminated film was prepared in the same manner as in Example 36 except that the molding was performed as described above, and the amount of acetaldehyde and the carbon dioxide gas barrier property of the laminated film after stretching were evaluated. Table 9 shows the results.

[0208]

Example 38 Instead of polyethylene terephthalate (A-7), a naphthalenedicarboxylic acid copolymer (naphthalenedicarboxylic acid: terephthalic acid (molar ratio) = 8: 92,
Ethylene glycol: diethylene glycol (molar ratio)
= 97: 3, intrinsic viscosity 0.85 dl / g, acetaldehyde content 2 ppm) were molded in the same manner as in Example 32, except that it was molded as a raw material for the inner and outer layers. A part of the mouth of the bottle was cut, and the amount of acetaldehyde was analyzed.
As in Example 32, the carbon dioxide gas barrier properties were evaluated. Table 9 shows the results.

[0209]

Example 39 The polyester produced in Example 11 was vacuum-dried at 150 ° C. for 16 hours and used as a raw material for an intermediate layer of a co-extruder manufactured by Hitachi Zosen. Polyethylene terephthalate (A-7) was heated at 150 ° C. A layered sheet having a thickness of 0.3 mm was formed using the material dried in vacuum for 16 hours as a raw material for an inner layer and an outer layer. The acetaldehyde content and carbon dioxide gas barrier properties of the laminated sheet were evaluated. Table 9 shows the results.

[0210]

[Table 9]

[0211]

Comparative Example 6 Polyethylene terephthalate (A-7): 90 parts by weight and polyethylene isophthalate copolymer (B-5): 1
0 parts by weight and 150 ppm of magnesium stearate were dry-blended to form a bottle in the same manner as in Example 18, and the amount of acetaldehyde and the carbon dioxide gas barrier property were evaluated. Table 10 shows the results.

[0212]

Comparative Example 7 Polyethylene terephthalate (A-7): 80 parts by weight and polyethylene isophthalate copolymer (B-5): 2
0 parts by weight and 150 ppm of magnesium stearate were dry-blended to form a bottle in the same manner as in Example 18, and the amount of acetaldehyde and the carbon dioxide gas barrier property were evaluated. Table 10 shows the results.

[0213]

[Comparative Example 8] Polyethylene terephthalate (A-7)
As a raw material of the outer layer, a polyethylene isophthalate copolymer
Using (B-5) as a raw material for an intermediate layer, a bottle was molded in the same manner as in Example 32, and the amount of acetaldehyde and carbon dioxide gas barrier properties were evaluated. Table 10 shows the results.

[0214]

Comparative Example 9 Naphthalenedicarboxylic acid copolymer (naphthalenedicarboxylic acid: terephthalic acid (molar ratio) = 8: 9
2, ethylene glycol: diethylene glycol (molar ratio) = 97: 3, intrinsic viscosity 0.85 dl / g, acetaldehyde content 2 ppm) as a raw material for the inner and outer layers, and a polyethylene isophthalate copolymer (B-5). A bottle was formed in the same manner as in Example 32 as a raw material for the intermediate layer, and the amount of acetaldehyde and the carbon dioxide gas barrier property were evaluated. Table 10 shows the results.

[0215]

[Table 10]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Koji Niimi, Inventor 6-1-2, Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Inside Mitsui Chemicals, Inc. (72) Shoji Hiraoka, Waki-cho, Kuga-gun, Yamaguchi Prefecture 6-1-2 Waki, Mitsui Chemicals, Inc. (72) Inventor Katsuyuki Sakai 1-2-1, Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Inside Mitsui Chemicals, Inc. (72) Inventor Hitoshi Tsuboi Yamaguchi Mitsui Chemicals Co., Ltd., 1-2 1-2 Waki, Waki-machi, Kuga-gun

Claims (10)

[Claims] 1. A dicarboxylic acid derived from a dicarboxylic acid containing terephthalic acid and isophthalic acid, and a diol derived from a diol containing ethylene glycol and 1,3-bis (2-hydroxyethoxy) benzene. (I) 15 to 99.5 mol% of the structural unit derived from terephthalic acid, and 0.1 to 0.5 mol% of the structural unit derived from isophthalic acid, based on all dicarboxylic acid structural units.
(Ii) 25 structural units derived from ethylene glycol based on all diol structural units.
-99.5 mol%, and the constitutional unit derived from 1,3-bis (2-hydroxyethoxy) benzene is 0.5 to 75%.
Mol%, intrinsic viscosity in the range of 0.5 to 1.5 dl / g, melting point (Tm (° C)) measured by differential scanning calorimeter
Is composed of a polyester satisfying the following general formula [I]: [1 / 527-0.0017 · ln (1- (m _I + m _B ) / 200)] ⁻¹ -273 <Tm ≦ 265 ... [I] (In the formula, m _I is a ratio (mol%) of a structural unit derived from isophthalic acid in all dicarboxylic acid structural units, and m _B is 1,3-bis (2-hydroxyethoxy) benzene in all diol structural units. The ratio (mol%) of the structural unit derived from the above is shown.) A polyester pellet having a density of 1350 kg / m ³ or more. 2. The melting point (Tm (° C.)) of the following general formula [I ′]
The polyester pellet according to claim 1, which satisfies the following. [1 / 527-0.0017 · ln (1- (m _I + m _B ) / 200)] ^-1 -270 <Tm ≦ 265… [I '] 3. The polyester pellet according to claim 1, wherein the content of acetaldehyde is 20 ppm or less. 4. The polyester pellet according to claim 3, wherein the content of acetaldehyde is 10 ppm or less. 5. [A] polyethylene terephthalate having an intrinsic viscosity of 0.3 to 0.8 dl / g before solid phase polymerization; 99 to 20% by weight
And [B] a dicarboxylic acid constituent unit derived from a dicarboxylic acid containing terephthalic acid and isophthalic acid, and a diol constituent derived from a diol containing ethylene glycol and 1,3-bis (2-hydroxyethoxy) benzene Blend with a polyethylene isophthalate copolymer before solid phase polymerization having an intrinsic viscosity of 0.3 to 0.9 dl / g; 1 to 80% by weight; pelletizing the blend; and crystallization. A method for producing polyester pellets. 6. A method for producing polyester pellets, comprising subjecting the blend according to claim 5 to preliminary crystallization by heating and then subjecting to solid phase polymerization. 7. The method for producing polyester pellets according to claim 5, wherein the blend having a temperature-rise crystallization temperature of 190 ° C. or lower is subjected to solid-state polymerization. 8. [C] Polyethylene terephthalate having an intrinsic viscosity of 0.5 to 1.5 dl / g after solid phase polymerization; 99 to 20% by weight
And [B] a dicarboxylic acid constituent unit derived from a dicarboxylic acid containing terephthalic acid and isophthalic acid, and a diol constituent derived from a diol containing ethylene glycol and 1,3-bis (2-hydroxyethoxy) benzene Blend with a polyethylene isophthalate copolymer before solid phase polymerization having an intrinsic viscosity of 0.3 to 0.9 dl / g; 1 to 80% by weight; pelletizing the blend; and crystallization. A method for producing polyester pellets. 9. The method for producing polyester pellets according to claim 8, wherein the blend is crystallized and then subjected to solid phase polymerization. 10. A polyethylene isophthalate copolymer
[B] is (i) a structural unit derived from isophthalic acid is 50 to 98 mol%, a structural unit derived from terephthalic acid is 2 to 50 mol%, based on all dicarboxylic acid structural units, (ii) 15 to 99 mol% of structural units derived from ethylene glycol based on all diol structural units
Wherein the constituent unit derived from 1,3-bis (2-hydroxyethoxy) benzene is 1 to 85 mol%. .